Methods for collecting and loading yarns and apparatuses therefor

ABSTRACT

A method for collecting yarns and an apparatus therefor which are characterized by that yarns of a plurality of fibrous materials are held and collected by a running belt a part of which is made round into a cylindrical form, run at this state for a prescribed distance together with the belt, and are released from the belt in the collected form, and 
     a method for loading a bundle of yarns and an apparatus therefor which are characterized by that a cylinder tool which is provided with a ring whose inner diameter is expanded toward the top at one end of the tool is inserted into a cylindrical case, the bundle of yarns is loaded into the cylinder tool from the one end until the top end of the bundle is exposed to the other end of the case, then, the top part of the bundle and the case are held, and the cylinder tool is removed off toward the one end, as the bundle is allowed to remain in the case.

FIELDS OF THE ART

The present invention relates to methods for collecting yarns comprisinga plurality of fibrous substances more densely and loading the collectedyarns into a cylindrical case, and apparatuses therefor. Particularly,the present invention relates to improved methods for collecting hollowfibers, and loading them into a cylindrical case and apparatusestherefor, which are suitable for producing a hollow fiber type ofseparatory apparatus suitable for fluid separation.

BACKGROUND OF THE ART

In fluid separation apparatuses, there are several types of membraneforms for fluid separation, for example, plane membranes, tubes, hollowfibers, etc. Among them, hollow fibers have a large membrane area forthe size of the case, thus the fluid separation apparatuses therefromcan be advantageously made compact and easy to be operated. Today thistype of the fluid separation apparatuses are primarily used.

The process for producing fluid separation apparatuses of a hollow fibertype comprises (1) forming a bundle of hollow fibers of a prescribedcount, (2) loading the yarn bundle into a cylindrical case, for example,a plastic case, (3) potting the bundle of hollow fibers to both ends ofthe case with a resin such as polyurethane, (4) exposing fiber openingsby cutting both potted ends of the bundle and (5) fixing the product tothe headers.

Collection of hollow fibers into a bundle and encasement thereof havebeen mainly performed manually conventionally, thus the quality of theproducts tends to vary too widely, and the production efficiency remainslow, thus, the development of a new efficient production method has beendesired eagerly.

In the production of a bundle of hollow fibers of a prescribed count,the total cross-section of the bundle is generally formed into a flat,round or square shape, depending on the cases, and the cross section ofthe bundle is required to be almost the same as the inner cross sectionof the case, and the sizes of the cross section, namely the diameter, ifthe cross section is round, or the major and minor axes, if elliptical,or the length and width, if rectangular, should be the same as or just alittle smaller than those of the case, when a bundle is loaded into thecase.

When it satisfies these conditions, the bundle of yarn fibers formed canbe readily loaded into the case, but, if not, the shape of itscross-section should be modified.

Heretofore, it has been ordinary that the shape modification of thecross section is mainly performed manually because of the difficulty ofthe modification of the cross section by an apparatus. In addition, thebundle of hollow fibers which has been modified by hand is usuallyloaded into the case by hand carefully and slowly. Such handiwork,however, must largely rely on the art of each worker, resulting influctuations in the product quality as well as the productivity. Thepresent invention is to resolve these problems.

Moreover, with reference to the production of a fluid separationapparatus of a hollow fiber type such as a hemodialyzer, one ofconventional methods for loading a bundle of permselective hollow fibersinto the cylindrical case of a fluid separator comprises binding eachbundle of hollow fibers with a tape at both ends and pushing one end ofthe bundle forcibly by hand into the case, or connecting a stringthrough the cylindrical case to one end of the yarn bundle and pullingthe other end of the string to introduce the bundle into the case.

In these conventional methods, a skilled worker is required to adjustthe form of the fiber bundles by hand for inserting them into thecylindrical case one by one carefully, and such low efficiencies ofthese operations have been the bottle neck for efficient production ofthe fluid separation apparatuses of a hollow fiber type withproductivity increased. In addition, the friction with the wall surfaceon the insertion tends to disturb the parallelism of the hollow fibers,and sometimes causes deterioration such as breakage of the hollowfibers, which results in lower productivity of such fluid separators.

Recently, for example, Japanese Patent Laid-open No. 54711/1985 hasproposed a method that the bundle of hollow fibers is previously wrappedwith a sheet so that one end of the bundle is hidden, while the otherexposed, then inserted into one opening of the case from the hidden endand only the sheet is pulled out of the other opening, and JapanesePatent Laid-open No. 86,906/1986 has disclosed a method that the bundleof hollow fibers is previously wrapped with a cylindrical bag to which astring is attached at one end so that the other end of the stringcontacts one end of the hollow fiber bundle, and loaded into the outercase by introducing the wrapped bundle from the end to which the stringis attached into the protection cylinder case and pulling off thecylindrical bag by drawing the string. The preliminary operation to wrapthe hollow fiber bundle, however, are very complicated, in particular,the process tends to become complicated, when the bundle is loaded intoa cylindrical case by an automated system. Thus, further improvement hasbeen desired.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide improved methods forcollecting a bundle of fiber yarns and an apparatus therefor whichovercome these conventional defects, with production efficiency andstability increased. Particularly, an object of the present invention isto improve the method for collecting a bundle of hollow fibers,comprising one step of the process for producing fluid separationapparatuses of a hollow fiber type where highdensity loading of thebundle is required.

Another object of the present invention is to enable the production offluid separation apparatuses of a hollow fiber type in stabilized andincreased productivity by optimizing the process for loading a bundle ofhollow fibers into a cylindrical case for automation.

The inventors have made an intensified investigation to achieve suchobjects and reached the yarn-collecting method and apparatuses thereforof this invention by finding that it is very effective to hold saidyarns with an endless belt means.

In addition, the present inventors have found that a bundle of hollowfibers can be loaded into a cylindrical case efficiently and stablywithout any adverse effect on the bundle, by inserting previously acylinder tool having a tapered open ring at one end into the cylindricalcase first, then loading the bundle of said yarns from the taperedopening through the cylinder tool into the case, and thus, reached theloading method and apparatuses therefor of this invention.

In other words, the present invention comprises the following:

A method of collecting yarns in a form of a bundle which ischaracterized by the following steps in combination, holding said yarnsby a running belt means a part of which is made round into a cylindricalform by closing tight, moving said yarns with the belt means for apredetermined distance while being held by the belt means, and thenreleasing said yarns from the belt means;

An apparatus for collecting yarns in the form of a bundle, whichcomprises a means for feeding said yarns, and a belt means which iscapable of holding said yarns by being made into a cylindrical form,moving with said yarns for a predetermined distance while holding saidyarns and then releasing said yarns;

A method of loading a bundle of yarns into a cylindrical case which ischaracterized by following steps in combination, inserting a cylindertool having a ring having an inner diameter which is expanded toward thetop of the ring at one end of the cylinder tool into the cylindricalcase, loading the bundle of yarns into the cylinder tool from said oneend until the end of the bundle is exposed at the other end of the tool,holding both the exposed end of the bundle and the cylindrical case, andthen extracting the cylinder tool toward said one end of the tool as thebundle is allowed to remain in the cylindrical case; and

An apparatus for loading a bundle of yarns which comprises a means forfeeding a bundle of yarns whose at least one end is wound with a tapingmaterial, a means for fixing a cylinder tool having a ring whose innerdiameter is expanded toward the top of the ring at one end of the tool,a means for holding and transferring the cylindrical case, and a meansfor holding the end of the yarn bundle and transferring the bundle, anda means for controlling a series of the following operations: puttingthe cylindrical case on the cylinder tool from the other end of thetool, inserting the bundle of yarns into the tool from said one end ofthe tool, until the end of the bundle is exposed to the other end of thetool, then, the end of the bundle is held and the case and the bundleare simultaneously moved toward the other end of the tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 schematically show the outline of a preferable embodimentof a means for collecting yarns according to the present invention.

FIG. 1 is a front view, while FIG. 2 is a plane view of the apparatus.In these figures, 1 is a bundle of hollow fibers, 2 is the endless beltmeans, 3 is a belt-rounding jig means, 4 is a collecting nozzle means, 5is a cylindrical case, and 6,7 and 8 are rollers driving the endlessbelt means. 9 represents one end of a bundle of hollow fibers.

FIGS. 3 through 6 show schematically a preferable embodiment of eachstep of a process for loading a bundle of yarns according to the presentinvention. FIG. 3 is an outline of the cylinder tool itself, FIG. 4 isan outlined cross-section where the cylindrical case is put on thecylinder tool, FIG. 5 is an outlined cross-section where the bundle ofhollow fibers is loaded into the case, and FIG. 6 shows a state whereone end of the bundle of hollow fibers and the cylindrical case areheld.

In these Figures, 21 is a ring having tapered opening, 22 is the innersurface, 23 is a supporter, 24 is the part to be cut, 25 is a sleeve, 26is the cylindrical case, 27 is the bundle of hollow fibers, 28 is anadhesive tape and 29 and 30 are holding means. The best embodiment forcarrying out the invention is set forth below.

FIG. 1 is a front view showing the structure of a yarn-collectingapparatus which is an embodiment of this invention, while FIG. 2 is aplane view showing the state where a bundle of hollow fibers is suitablycollected by means of an endless belt means 2, a belt-rounding jig means3 and a collecting nozzle means 4 into an almost appropriate shape andloaded into the case 5. The endless belt means 2 is driven by rollers 6,7 or 8. The arrows in the Figures indicate the moving directions of thebundle of hollow fibers, the belt means or rollers.

In other words, a bundle of hollow fibers 1 is extended in almostparallel preliminarily and fed to the apparatus according to theinvention, in which said yarns are collected into a bundle of yarns moredensely, as it runs with the endless belt means 2 while being held withthe belt means a part of which is made round into a cylindrical form bythe belt-rounding jig means 3.

At the start, the bundle of hollow fibers 1 may be fed near thebelt-rounding jig means 3 by holding it with a robot (not shown in theFigure), or it is also possible to install a belt conveyer (not shown inthe Figure) which runs at the same speed as the endless belt means does,behind the roller 8, and drives it synchronously with the roller 8.

In some cases, the bundle of yarns 1 rises, as it is collected from awide form to a dense and narrow form, until it expands over from theoverlapped belt edges. In such a case, the expansion can be prevented byplacing a roller or a guide 10 on the position to press the expansion ofthe bundle of said yarns 1.

The endless belt means 2 is made round into a cylindrical form, justlike a layer sheet in a rolled "SUSHI", after it passes through thebelt-rounding jig means 3.

The bundle of hollow fibers 1 is collected by the belt-rounding jigmeans 3 and shaped into the finally right cross-sectional form by thecollecting nozzle means 4, then loaded into the case 5 which is locatedin front of the bundle in this situation. It is a matter of course thatthe shape of the collecting nozzle means 4 should be designed accuratelyto the inner cross section of the case 5. The belt-rounding jig means 3may be integrated with the collecting nozzle means 4, or thebelt-rounding jig means 3 can also work as a collecting nozzle means 4or vise versa.

The bundle of hollow fibers 1 loaded in the case 5 is cut with a cuttersuch as a knife in an appropriate length, by allowing the endless beltmeans 2 to stop tentatively, when the top of the bundle 9 comes to aprescribed position, and binding the bundle 1 with an adhesive tape 14or the like at a predetermined position between the collecting nozzlemeans 4 and the case 5, so that the adhesive tape 14 is left at bothends after cutting. The endless belt means 2 is tentatively stopped by,for example, using a switch equipped with a light detector 12 at the topend 9. After completion of cutting, the case into which the bundle ofhollow fibers has been loaded is removed and a new empty case is set tothe position and the next operations can be repeated automatically.

When the endless belt means 2 is made round into a cylindrical form bythe jig means 3, the reversion of overlapped belt edges is undesirableduring the operation, because a part of said yarns in the bundle arenipped and damaged by the endless belt means 3. In order to prevent suchphenomena, guide pins may be set before and after the jig means 3 tomake the overlap of the belt edges constant or the jib means 3 may bebored perpendicularly to the belt-running direction and pressurized airis introduced from the hole to make the overlap constant. The endlessbelt means 2 runs at such a state as the bundle of said yarns 1 is heldwith the endless belt means, and the bundle of said yarns 1 also runs atthe same speed as the belt means 2 does resultantly.

The bundle of said yarns 1 goes to the collecting nozzle means 4, andthe nozzle means 4 is required to have the outlet of an appropriateshape suitable for the bundle of hollow fibers 1 and the inner crosssection of the case 5. The collecting nozzle means 4 can decide thefinal cross section of the bundle of hollow fibers 1, and allows theendless belt means 2 to turn to the side opposite to said yarns andunfold the belt means 2. Thus, the distance from the point where thebundle of hollow fibers is held with the endless belt means 2 to thepoint where the holding is released, is practically about 5 cm to about200 cm, preferably 10 cm to 200 cm.

Any belt can be used in this invention as long as it suits the object ofthis invention, but in general, rubber belts or cloth belts can bepreferably used. Examples of such belts are a cloth-layered rubber beltwhich has a structure in which a couple of cloth sheets coated with anadhesive rubber on both of their surfaces are laminated and covered withcovering rubber sheets, respectively, a steel-code belt which isprepared by laminating covering rubber sheet onto both surfaces of asteel code layer, a rubber belt made of only rubber or a woven fabricbelt which is prepared by coating or impregnating woven cloth with aresin, and a cloth-layered rubber belt, a woven fabric belt or the likeis preferred. The material of the covering rubber sheets is notparticularly limited, but natural rubber, isoprene rubber, butyl rubber,neoprene rubber, NBR, SBR, urethane rubber, or silicone rubber can becited practically. Examples of resins for coating and impregnation arepolyurethane, silicones or epoxide resins. The belt means for thisinvention is practically flat, 0.5 to 2 mm thick and 4 to 20 cm wide,and made endless into a ring.

The method for loading a bundle of yarns and an apparatus therefor ofthis invention are characterized by use of a cylinder tool which has atapered opening ring whose diameter is expanded toward the end. Apreferable embodiment of such a cylinder tool is shown in FIG. 3. Inother words, the cylinder tool in FIG. 3 has, at one end, a ring 21whose inner surface 22 is expanded toward the end, and has a supporter23 for fixing the ring 21, further includes a substantially cylindricalsleeve 25 which is made by overlapping the cut edges 24 of a sheet andis tapered toward the opposite end of the ring 21.

A preferred example of the ring are a metallic ring which is made ofstainless steel or aluminum whose inner surface is at least coated witha fluorine-containing resin such as polytetrafluoroethylene or asilicone resin or satin-finished to reduce the friction with the bundleof hollow fibers, or a plastic ring which is made of afluorine-containing resin or the like. The sleeve is preferably madefrom a plastic sheet such as a fluorine-containing or olefin resin sheetand, may be embossed, if necessary, to reduce the friction with thebundle of hollow fibers.

The method for loading of this invention is such that a cylinder tool isinserted into a cylindrical case for a fluid separation apparatus, abundle of yarns such as a bundle of permselective-hollow fibers isloaded from the ring-equipped side into the inside of the cylinder tool,until the top end of the bundle of the yarns is exposed to the other endof the cylinder case. FIGS. 4 and 5 show these preferable embodiments.In other words, a cylindrical case 26 is put on the cylinder tool asshown in FIG. 3 equipped with a ring 21 and a sleeve 25 from the top ofthe sleeve, as shown in FIG. 4, then, a bundle of hollow fibers 27 whichis bound with adhesive tapes 28 at both ends is loaded into the sleeve25 from the side of the ring 21, as shown in FIG. 5. A long bundle offibers which is wound with an adhesive tape only at the top end also maybe loaded into the sleeve only at the head part. In this case, it ispreferred that the bundle of said yarns is loaded into the case by aprescribed length, wound with an adhesive tape near the ring 21, and theloaded bundle is cut off with a knife or the like.

In addition, the loading method of this invention is such that theexposed part of the bundle of hollow fibers loaded into the case and thecase are held and the cylinder tool is pulled off to the ring side, asthe bundle is left in the case. The preferred embodiment is shown inFIG. 6. In other words, the product obtained by operations as shown inFIGS. 3 through 5 is supported by holding the case 26 with a holdingmeans 29 and the exposed end of the hollow fiber bundle 27 with aholding means 30, respectively, and both of them are transferred at thesame speed to the side of holding means 30 to pull out only the cylindertool having a ring 21 which is fixed by a means for fixing and a sleeve25 whereby a cylindrical case packed with a bundle of hollow fibers isobtained.

Thus, a bundle of permselective hollow fibers can be loaded into acylindrical case stably and efficiently without damage to the bundle.The cylinder tool may be made movable, but the stationary installationis more suitable for automation, as shown in FIGS. 3 through 6, withproductivity increased. In the loading method according to thisinvention, in case that the cylinder tool is fixed, automated loadingbecomes possible by combining the means for feeding a bundle of hollowfibers with a means for holding and transferring the cylindrical case asshown in FIGS. 1 and 2, and by providing a means for controlling eachmeans to repeat a series of processes in order for putting thecylindrical case on the cylinder tool (FIG. 4), then loading a bundle ofhollow fibers into a cylindrical case (FIG. 5), and transferring thecase packed with the yarn bundle (FIG. 6).

Said yarns in this invention may be any kinds of fibrous materials ofplural counts, however, a plurality of hollow fibers are more effective.Especially, examples of fibrous material which are preferably used inthis invention are hollow fibers having permselectivity, which can beused in fluid separation such as liquid separation, for example,dialysis, reverse osmosis, ultrafiltration, or gas separation, forexample, oxygen enrichment. The fibrous material also may be hollowfibers which are used as a support for forming permselective membranesby coating or the like. The hollow fibers particularly suitable for thepresent invention can be used in treatment for body fluid such ashemodialysis, blood filtration, plasma separation, ascites treatment orartificial lungs.

The material of such hollow fibers is not particularly limited, butcellulose, cellulose esters, polyethylene-vinyl alcohol copolymer,poly(methyl methacrylate) polysulfone, polyether sulfone,polyacrylonitrile and other polymers can be used in case of body fluidtreatment.

The cross section of such hollow fibers is usually round, but it may bemodified, for example, a finned shape or two lines of hollow fibersbonded to each other at their external periphery. Further, the hollowfibers may be crimped, or may be wound in spiral with other fine fibers.

The hollow fiber has an inner diameter 10 to 1,000 microns, preferably20 to 300 microns, while its wall thickness is 3 to 300 microns,preferably 5-100 microns, particularly 6-30 microns.

The count of said yarns in this invention is 2,000 to 200,000,preferably 5,000 to 20,000, because the effect of this invention isadvantageously manifested.

A fluid separation apparatus of a hollow fiber type can be produced moreeffectively and stably by the methods of this invention, and the fluidseparation apparatus can be used in fluid treatment such as reverseosmosis, ultrafiltration or dialysis, or gas treatment such as oxygenenrichment or helium separation. Particularly, the methods of thisinvention enables easy loading of a bundle of hollow fibers stably withincreased productivity, even in production of blood-treating apparatusessuch as a hemodialyzer, blood filter, plasma separator or artificiallung in which the damage of hollow fibers must be avoided to the utmost.

POSSIBILITY OF INDUSTRIAL USE

The method for collecting a bundle of yarns and an apparatus thereforaccording to this invention can automatically collect a bundle offibrous materials such as hollow fibers more densely, and canautomatically repeat a series of operations of loading the bundle ofsaid yarns into a case, stopping at an appropriate position and cuttingthe bundle of said yarns at a predetermined position, whereby a bundleof straightened yarns of almost equal length is readily obtained in avery high productive stability. Further, the operations of exchangingthe case loaded with a bundle of hollow fibers with a new, empty casealso can be automatically made.

The method for loading a bundle of yarns and an apparatus thereforaccording to this invention can load efficiently a bundle ofpermselective hollow fibers into a cylindrical case for a fluidseparation apparatus without damage to the bundle, and, in particular,an automated system which can conduct the method of this inventionenables loading of a bundle of hollow fibers in very high efficiency andincreased productivity.

In other words, the present invention is an epochmaking, big stride ofinnovation to bring about a great labor saving in the productionprocess, a great increase in productivity and a stabilization ofquality.

We claim:
 1. A method of collecting and forming yarns into a bundle,said yarns comprising 2,000 to 200,000 hollow fibers having apermselective wall, said method comprising:holding said yarns by arunning belt means; forming a part of said belt means into a cylindricalshape by compressing said part of said belt means, moving said yarnswith the belt means for a predetermined distance while said yarns areheld by the belt means, releasing said yarns from the belt means,loading a bundle of said yarns being released from said belt means intoa cylindrical case, stopping the running belt means, binding the bundlewith an adhesive taping material at a predetermined position between arelease position of said yarns being held and an inlet opening of thecase, and cutting said yarns.
 2. A method of collecting yarns accordingto claim 1, wherein the belt means is made into a cylindrical shape byintroducing the belt means into a belt-rounding jig means.
 3. A methodof collecting yarns according to claim 1, wherein said yarns are pressedto the belt means by a yarn-pressing means at the side opposite to thebelt means before said yarns move into the belt-rounding jig meanstogether with the belt means.
 4. A method of collecting yarns accordingto claim 1, wherein, after said yarns pass through a nozzle means whilebeing substantially held by the belt means, the belt means turning tothe side opposite to said yarns and unfolding to release said yarns. 5.A method of collecting yarns according to claim 1, wherein the beltmeans comprises an endless belt means.
 6. A method of collecting yarnsaccording to claim 1, wherein the predetermined distance is 5 to 200 cm.7. A method of collecting yarns according to claim 1, said methodfurther comprising the steps of:exchanging the case loaded with thebundle with a new cylindrical case, and starting the belt means to runagain.
 8. An apparatus for collecting and forming yarns into a bundle,comprising:a feeding means for feeding said yarns, said yarns comprising2,000 to 200,000 hollow fibers having a permselective wall, a belt meansfor holding said yarns by being formed into a cylindrical shape, andwhich moves with said yarns for a predetermined distance while holdingsaid yarns, and which then releases said yarns, and a detector means fordetecting that the released yarn bundle is moved and loaded into acylindrical case, said detector means comprising a non-contact typedetector.
 9. An apparatus for collecting yarns according to claim 8,wherein the belt means comprises an endless belt means which is drivenby a driving means.
 10. An apparatus for collecting yarns according toclaim 8, further comprising a cylindrical belt-rounding means for makingthe belt means into a cylindrical form, and a nozzle means through whichthe rounded belt means is passed with said yarns being held.
 11. Anapparatus for collecting yarns according to claim 8, further comprisinga controller means for controlling and stopping the running belt meansin response to an output by the detector means.
 12. An apparatus forcollecting yarns according to claim 8, further comprising a windingmeans for winding an adhesive tape around the yarn bundle at apredetermined position between a yarn releasing position and an inlet ofthe case, and a cutter means for cutting the bundle of yarns heldtogether with the adhesive tape.